Blast-furnace



A. B. CARSTENS.

BLAST FURNACE.

APPLICATION FILED 0512.5, 1919.

Patented 061. 18, 1921.

@ (2 32 a'vwamtoz 32 4 Sub 14412 113 mrro srar OFFICE.

ALEXANDER B. CARSTENS, OF MONTEREY, MEXICO, ASSIGNOR TO THE AMERICAN METAL COMPANY, LIMITED, A CORPORATION OF NEW YORK.

BLAST-FURNACE.

rename.

To all whom it may concern:

Be it known that I, ALEXANDER B. CAR- STENS, a citizen of the United States, residing at Monterey, Mexico, have invented certion of certain improvements and economies in the operation of such furnaces.

More specifically my invention contemplates the heating of the blast, prior to its introduction to the furnace, and the utilization, for this purpose, of fuels unsuitable for use directly in the furnace, and has for its object the provision of means for readily accomplishing this desirable result. Further objects and advantages of my invention will be apparent as it is better understood by reference to the following specification, when read in-connection with the accompanying drawing, in which I have illustrated two modes of applying my invention, without intention, however, to limit its application to the precise mechanical forms shown,

In the drawings;

Figure l is a longitudinal section through a twyer, showing my invention applied thereto; and

Fig. 2 is a similar view of a blast pipe with my invention applied thereto.

Coke is employed as a fuelin air blast furnace operations, for the double purpose of furnishing the carbon necessary for reduction, and the heat re uired tomaintain the reducing reaction. pecial grades of coke are required, and the fuel is relatively expensive, particularly in certain, localities, where other-\and cheaper fuels are, however, available.

I propose to utilize such cheaper fuels to provide at least a portion of the necessary heat for the reaction, thus permitting a reduction in the quantity of coke consumed, the latter fuel being primarily employed in furnishing reducing carbon. Other advantageous results follow from the practice. For example, a better heat control and consequent regulation ofthe reaction is posspecification of Letters Patent.

Patented eat. is, 1921.

Serial No. 343,437.

sible. The reducing operation will be concentrated in front of, or immediately above the twyers. It may develop, moreover, that by confining the reducing zone in the lower part of the furnace, a lighter burden and consequentlfr a lower blast pressure will be required. n iron blast furnaces, a portion of the cheaper fuel introduced as hereinafter described, may be burned inside the furnace with considerable economyv and improvement of the conditions which are characteristic of such furnaces.

My invention may be advantageously employed in lead-silver, copper, and iron blast furnaces, but it is to be understood that it is .capable of general application to furnaces of the blast type, in which coke is employed as a-fuel, to reduce the quantity of "coke required and to increase the efficiency of such furnaces.

In the drawing (Fig. 1) 5 indicates the wall or jacket of a blast furnace having a twyer opening 6. A twyer 7 is connected to the wall 5 and as illustrated is provided with a refractory lining 8, and an inlet 9 for the blast of air induced by a suitable blowing engine (not shown). The twyer is also preferably provided with an inspection opening 10 with a suitable cover 11.

The twyer 7 provides a combustion chamber and fuel is directed into this chamber from a burner 13 which may be of any suitable or well known type adapted for burning various combustibles as gas, oil or pulverized solid fuel. Preferably the fuel is led to the burner 13 through a pipe 14, and compressed air or steam is also supplied through a pipe 15 to insure initial combustion. A portion of the oxygen necessary for combustion is derived from the blast. Combustion of the "fuel directly in the blast in accordance with my invention insures the maximum efficiency of the fuel, all of the heat being conserved and carried directlyinto the furnace for utilization therein.

In Fig. 2 of the drawing, the application of my invention is substantially as hereinbefore described, except that the fuel is burned in a blast pi e which may supply a number of twyers. uch a pipe is illustrated at 16 and is provided with a refractory lining 17 and an inspect-ion hole 18. A burner 19 for fuel, as hereinbefore described, is disposed within the pipe 16 and is supplied with fuel through a pipe 20, and with compressed. air or steam through a pipe 21. The air of the blast furnishing oxygen to maintain combustion and the products of such combustion, mixing with the blast, insure distribution therein of the heat generated. In ironblast furnaces, the gas escaping from the furnace is combustible and may be utilized in the burners described, with greater efiiciency than is possible with indirect heating accomplished by the hot blast stoves now commonly employed in connection with such furnaces. The saving of fuel accomplished by direct heating of the blast by combustion gases and the immediate introduction of the mixture of hot combustion products and air is sufficiently apparent. Moreover, the amount of fuel, introduced through the burners, may be readily varied and an excess may be supplied, so that a portionis carried into and burned within the furnace in contact with the materials treated therein. I

It is to be understood that in utilizing the invention, a material saving may be made in the expensive coke necessarily employed in ordinary blast furnace operations by introducing an excess of the cheaper fuel to the blast, a portion of the fuel being burned in the combustion chamber while the surplus passes with the combustion products from the combustion chamber to the furnace, where it is burned in direct contact with the ore. Under these circumstances, a limited quantity of carbon may be mixed with the ore forming the burden of the furnace. The

fuel required for heat is supplied through the twyers, while the carbon required for directreduction of the ore is mixed therewith before the ore is introduced to the furnace. By this mode of operation, the heat is concentrated in the lower portion of the fur nace, the rate of reduction is increased and a furnace of given size has a considerabl enlarged capacity.

ifs noted,-my invention is not directed to specific details of the structure employed, it

being apparent that such details are matters of design which will be effected by the particular character of the furnace, the volume and characterof the blast and the quantity of heat it is desirable to supply.

Various changes may, therefore, be introduced within the scope of the appended claims without departing from the invention 0r sacrificing any of its advantages.

I claim:

1. In' a metallurgical blast furnace," the combination of a conductor for the blast providing a combustion chamber, means for supplying a blast of oxidizing gas to the combustion chamber, a fuel burner within said chamber, and means for supplying fuel and an oxidizing agent to said burner, said fuel being burned within said chamber so thatthe combustion products thereof commin le with said blast.

2. n a metallurgical blast furnace, the combination of a conductor for the blast providing a combustion chamber, means for supplying a blast of, oxidizing gas to the combustion chamber, a fuel burner within said chamber, and means for supplying. fuel and an oxidizing medium to said burner, a portion of the oxygen for combustion being derived from said blast with which the products of combustion are comming led.

3. In a metallurgical blast furnace, the combination of a blast twyer having a combustion chamber, means for supplying a blast of oxidizing gas to the combustion chamber, a fuel burner within said chamber, and means for supplying fuel to said burner,"the blast mixed, with products of combustion of said fuel being conveyed by said twyer directly into, said furnace.

4. In the operation of metallurgical blast furnaces, the method which comprises, supplying a blast of air to said furnace, introducing an excess of fuel to said blast, burning a portion of said fuel with said blast before it enters said furnace and conveying theremainder of said fuel with the mixed blast and combustion products to said furnace 5. A method of improving metallurgical operations requiring direct reduction with carbon in blast furnaces which comprises, employing a limited quantity of carbon in said furnace, introduclng'a blast of air-and supplying heat by burning fuel directly in said blast, thereby concentrating the heat in the lower portion of said furnace.

6. A method of improving metallurgical operations requiring direct reduction with carbon in blast furnaces, which comprises, employing a limited quantity of carbon'in saidfurnace, introducing a blast of air, and supplying heat by burning fuel directly in said blast, said fuel being provided in excess so that a portion thereoff is introduced into said furnace, thereby concentrating the heat I in the lower portion of said furnace.

In testimon whereof I affix my signature.-

ALE ANDER B. GARSTENS. 

